18428-76-7Relevant academic research and scientific papers
Li+-Induced fluorescent metallogel: A case of ESIPT-CHEF and ICT phenomenon
Dixit, Manish Kumar,Dubey, Mrigendra
, p. 23762 - 23772 (2018/09/29)
A fluorescent metallogel (1percent w/v) has been synthesized from non-fluorescent ingredients viz. the smallest possible low molecular weight aromatic symmetrical ligand H2SA (1) and LiOH in a chloroform and methanol mixture. The chelation of Li+ is not only responsible for the inhibition of excited state intramolecular proton transfer (ESIPT) or the origin of fluorescence through chelation enhanced fluorescence (CHEF) in 1, but also for aggregation leading to gelation. The metallogel obtained from 1/Li+ reveals a fibrous morphology while 1 with other, bigger size, alkali metal ions like Na+/K+/Cs+ demonstrates the growth of crystals with different shapes. The effect of the size of the alkali metal ion over gel formation is well explored by FTIR, UV-vis, fluorescence, average lifetime measurements, SEM and PXRD. The metallogel shows multi-stimuli responsive behaviour towards thermal and mechanical stress as well as reswelling properties. The regioisomer H2PBA (2) also shows emission upon treatment with LiOH due to the presence of intramolecular charge transfer (ICT), this is well established by various experiments. The mechanism of gel formation is well established by FTIR, 1H NMR, UV-vis, fluorescence, lifetime measurements, SEM and single crystal and powder XRD instrumental techniques. The involvement of various phenomena in gel formation has been further supported by other synthesized model compounds viz. H2MBA (3), PMO (4), H2SEA (5) and H2SPA (6). True gel phase material is proved by detailed rheological experiments.
An efficient synthesis of perhydro[1,2,4]triazolo[1,2-a][1,2,4]triazole-1,5-dithiones catalyzed by TiO2-functionalized nano-Fe3O4 encapsulated-silica particles as a reusable magnetic nanocatalyst
Safari, Javad,Javadian, Leila
, p. 104973 - 104980 (2015/12/26)
Immobilization of a nano-TiO2 catalyst on the surface of a magnetic SiO2 support was performed through the reaction of a Fe3O4@SiO2 composite with Ti(OC4H9)4via a simple process. The Fe3O4@SiO2-TiO2 nanocomposite was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and a vibrating sample magnetometer (VSM). The Fe3O4@SiO2-TiO2 nanocomposite has been found to be an efficient catalyst for the synthesis of perhydro[1,2,4]triazolo[1,2-a][1,2,4]triazole-1,5-dithiones from the condensation of various aldazines and potassium thiocyanate in acetonitrile solvent at room temperature. It has been found that the nanocatalyst was recycled for up to 6 cycles with minimal loss in catalytic activity. The purpose of this research was to provide an easy method for the synthesis of perhydrotriazolotriazole derivatives by a robust and magnetically recoverable catalyst.
CONDENSATION OF p-(DIMETHYLAMINO)BENZALDEHYDE WITH HYDRAZINE IN A MICELLAR MEDIUM
Yatsimirskii, A. K.,Yatsimirskaya, N. T.,Krivova, S. B.
, p. 752 - 757 (2007/10/02)
The rate of the condensation of p-(dimethylamino)benzaldehyde with hydrazine in aqueous solution and the yield of the product (the amine) rise by two orders of magnitude in presence of micelles of sodium dodecyl sulfate.It was found that the micellar effect in the kinetics is manifested at the first dimolecular stage of the reaction of the aldehyde with hydrazine and is explained by the concentrating of the reactants in the micelles.The rate constants of the condensation of hydrazine with a number of substituted benzaldehydes conform to the Hammett equation with a low positive value of ρ.
Aspects of acyclic azine chemistry -- I. The effect of structure and solvents on the electronic absorption spectra of benzaldazine, o-, m- and p-hydroxybenzaldazines
Okafor, E. Chukwuemeka
, p. 207 - 212 (2007/10/02)
The electronic absorption spectra of benzaldazine, o-, m-, and p-hydroxybenzaldazines have been separately examined in various solvents (20 solvents and solvent mixtures).The observed three groups of bands designated as α (200-225 nm), β (289-307 nm) and γ (352-375 nm) are attributed to ?* IAu IAg) are out-of-plane (Ξ) polarized while all ?* IBu IAg) are in plane (x,y) polarized.In the rationalization of data, the theory of resonance has been employed where deemed useful.The shifts of bands with solvents have been traced.
